What Is Heat Shrink Tubing?
Heat shrink tubing is made of a plastic material that shrinks around a wire and creates a strong seal. It can protect against abrasion, mechanical strain and environmental threats, especially on joints or termination points. It reduces in size radially but only shrinks a very small amount longitudinally, meaning it mostly retains its length for easy application. Some heat shrink tubing options have more longitudinal shrinkage than others, so make sure your application can handle your tubing’s shrinkage rating.
Heat shrink tubing is commonly manufactured in polyolefin material. There are tubing products designed with higher temperature ratings and without shrinking abilities, but polyolefin is standard. It can withstand high temperatures up to around 125 degrees Celsius, making it appropriate for use in demanding environments. Standard sizes are 2:1, 3:1 and 4:1 — these ratios refer to the degree to which a piece of tubing will shrink down from its original size. For instance, a piece of tubing with a 2:1 ratio will shrink to half its original size.
Tubing is also available in flexible and adhesive options. Flexible tubing is used on wires that need to bend, and adhesive-lined tubing uses glue on the inner layer that melts as heat is applied to make a more secure connection once it dries. Our heat shrink tubing products for sale online come in multiple colors to choose from.
Some of the common reasons for using heat shrink tubing include:
- Color coding.
- Adding resistance to abrasion, strain and small impacts.
- Adding electrical insulation.
- Bundling wires and wire harnesses together.
- Changing the texture or finish of an object.
It’s important to consider the dielectric strength of your application, too. Certain heat shrink tubing materials support higher voltages than others, so you must ensure your tubing can handle a voltage that’s the same or higher than that of the wire.
Everything You Need to Know About Heat Shrink Tubing
Are you aware that there are instances where a fire is often caused by a house’s faulty wiring system? These are instances where the electrical wires often get exposed to extreme heat or become prone to abrasions or short circuits. These accidents would have been prevented if heat shrink tubing was used to protect the electrical wires from exposure.
Heat shrink tubing is a mechanically expanded tube or tape that you can use to protect electrical wires or some minor electrical parts from harsh environmental elements. You can also use it to improve the insulation of the wires or bundle them so they won’t get tangled.
Heat shrink tubing is usually made of polyolefin or nylon, materials that shrink whenever they are heated. After they cool off, they return to their original relaxed state or diameter. There are many different types of shrink tubing, all designed for different purposes.
- Fluoropolymer: Fluoropolymer tube or polytetrafluoroethylene (PTFE) is a type of shrinkable tubing that has a considerable amount of resistance to punctures and harmful chemicals. It also has a very low friction coefficient and has a wide range of operating temperatures.
- Viton: Viton is another type of shrink tubing that has a huge amount of chemical resistance. Often used in hydraulic equipment, it is very flexible and can operate at a very high temperature. These properties make Viton one of the most effective shrink tubing options whenever extreme temperature is a factor to consider.
- Elastomeric: Elastomeric shrink tubes can maintain very high flexibility even if they are subjected to very low temperatures. The tubes are highly resistant to chemicals such as petrol and diesel and can withstand the most severe environmental elements. They are also highly resistant to abrasion.
- Adhesive polyolefin: Adhesive polyolefin shrinkable tubing is often used in the military, railway and aerospace industries. This type of tube tends to shrink very fast and is highly flexible. It is also widely manufactured and considered the most commonly used type of shrink tubing. However, it does have poor resistance to ultraviolet (UV) light – so low that only black polyolefin tubes are recommended for outdoor use.
- Silicone rubber: Silicone rubber tubings offer excellent abrasion resistance and flexibility. Fluorinated ethylene propylene or FEP is another type of shrink tubing which is considered as the cheaper alternative to PTFE. Polyvinylidene fluoride is usually recommended for high-temperature usage.
Shrink tubings are usually available in a wide range of colors. This makes it easier for people to color-code their connections.
Heat shrink tubing also comes with varying shrink temperatures. This refers to the heat required to shrink the tubing. Polyolefin heat shrink tubing usually requires higher temperatures than PVC tubing. Typically, this temperature is applied via a hand-held heat gun. However, manufacturers may use a flow-through oven for more thorough heat exposure for high production levels. Make sure your heat shrink tubing has a shrink temperature that meets the capabilities of your heating method.
Heat Shrink Ratios
There are a few different types of polyolefin to be aware of when purchasing heat shrink tubing. The main thing you need to know is the wire’s heat shrink ratio.
Basic polyolefin tubing has a 2:1 heat shrink ratio. You want to place your hook-up wire right in the middle because the tubing needs to grab onto the wire when it’s shrinking. Otherwise, it will slip around and you might be able to pull it off. If you use tubing that’s too small, it could tear it because it’s trying to shrink more than possible.
You can also get the same polyolefin heat shrink tubing in the 3:1 or even 4:1 shrink ratio. These larger ratios mean you can more easily slide them around larger components, such as wire harnesses. Many also come with adhesive glue on the inside, so you can permanently shrink the tubing onto the hook-up wire. If you use adhesive, it will be very difficult to remove the tubing, and if you can take it off, it will leave residue on the wire.